title: Effect of interleukin-6 polymorphisms on human longevity: a systematic review and meta-analysis.
abstract: Several studies have assessed changes in frequency of -174 interleukin (IL)-6 single nucleotide polymorphism (SNP) with age. If IL-6 tracks with disability and age-related diseases, then there should be reduction, in the oldest old, of the frequency of homozygous GG subjects, who produce higher IL-6 levels. However, discordant results have been obtained. To explore the relationship between this polymorphism and longevity, we analyzed individual data on long-living subjects and controls from eight case-control studies conducted in Europeans, using meta-analysis. There was no significant difference in the IL-6 genotype between the oldest old and controls (Odds Ratio [OR]=0.96; 95% C.I.: 0.77-1.20; p=0.71), but there was significant between-study heterogeneity (I2=55.5%). In a subgroup analyses when male centenarians from the three Italian studies were included, the frequency of the IL-6 -174 GG genotype was significantly lower than the other genotypes (OR=0.49; 95% C.I.: 0.31-0.80; p=0.004), with no evidence of heterogeneity (I2=0%). Our data supports a negative association between the GG genotype of IL-6 SNP and longevity in Italian centenarians, with males who carry the genotype being two times less likely to reach extreme old age compared with subjects carrying CC or CG genotypes. These findings were not replicated in other European groups suggesting a possible interaction between genetics, sex and environment in reaching longevity.
authors.affiliation: Dipartimento di Biopatologia e Metodologie Biomediche, Università di Palermo, Palermo, Italy.
authors.forename: Danilo
authors.initials: D
authors.lastname: Di Bona
authors.forename: Sonya
authors.initials: S
authors.lastname: Vasto
authors.forename: Cristiano
authors.initials: C
authors.lastname: Capurso
authors.forename: Lene
authors.initials: L
authors.lastname: Christiansen
authors.forename: Luca
authors.initials: L
authors.lastname: Deiana
authors.forename: Claudio
authors.initials: C
authors.lastname: Franceschi
authors.forename: Mikko
authors.initials: M
authors.lastname: Hurme
authors.forename: Eugenio
authors.initials: E
authors.lastname: Mocchegiani
authors.forename: Maeve
authors.initials: M
authors.lastname: Rea
authors.forename: Domenico
authors.initials: D
authors.lastname: Lio
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Candore
authors.forename: Calogero
authors.initials: C
authors.lastname: Caruso
mesh_terms: D000369:Aged, 80 and over; D004777:Environment; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D008136:Longevity / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide
chemical_list: D015850:Interleukin-6